<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <div id="app">
        <div>
            <span>全选:</span>
            <input  type="checkbox" v-model="isAll"/>
            <button @click="reverse">反选</button>
            <ul>
                <li v-for="(item,index) in arr">
                    <input type="checkbox" v-model="item.checked"/>
                    <span>{{item.name}}</span>
                </li>
            </ul>
        </div>
    </div>
    <script src="./vue.js"></script>
    <script>
        const app = new Vue({
            el: '#app',
            data: {
                arr: [
                    {
                        name: "猪八戒",
                        checked: false,
                    },
                    {
                        name: "孙悟空",
                        checked: false,
                    },
                    {
                        name: "唐僧",
                        checked: false,
                    },
                    {
                        name: "白龙马",
                        checked: false,
                    },
                ],
            },
            computed : {
                isAll :{
                    get () {
                      //every 判断每个复选框的状态
                      return this.arr.every(item=>item.checked)
                    },
                    //当值发生改变之后,重新渲染,将值赋给checked
                    set (newVal) {
                      this.arr.forEach(item=>item.checked=newVal);
                    }
                }
            },
            methods: {
              reverse(){
                this.isAll=! this.isAll
              }
            }
        })
    </script>


</body>

</html>